US media has reported that the Pentagon had been in charge of a secret multi-million dollar programme which investigated Unidentified Flying Objects (UFOs).

Few officials knew about the programme, which started in 2007 and was reportedly terminated in 2012.

The Advanced Aerospace Threat Identification Programme, as it was known, was formed based on an idea of former Democratic senator Harry Reid, at the time majority leader in the Senate.

In comments to the New York Times, he said “I'm not embarrassed or ashamed or sorry I got this thing going. I've done something that no one has done before.”

He also tweeted that “If anyone says they have the answers, they’re fooling themselves.”

“We don’t know the answers but we have plenty of evidence to support asking the questions. This is about science and national security. If America doesn’t take the lead in answering these questions, others will.”

The programme reportedly cost the Department of Defence more than $20 million (€17 million), but was brought to an end in a cost-saving effort.

Despite this, officials have, according to the reports, persisted in their investigations of UFO sightings.

An ex-member of Congress staff told Politico that the purpose of the programme may have been to surveil the technological developments of rival foreign countries.